Tom K. answered 11/08/20
Knowledgeable and Friendly Math and Statistics Tutor
As csc(θ) = 5, sin(θ) = 1/csc(θ) = 1/5
As we are in Quadrant 2, cos(θ) = -√(1 - sin2(θ)) = -√(1 - (1/5)2) = -√24 / 5
Thus, cot(θ) = cos(θ)/sin(θ) = -√24 / 5/(1/5) = -√24 = -2√6
cot(θ - 2π) =cot(θ)
cot(π - θ) = -cot(θ)
Thus, cot(θ) - cot(π - θ) + cot(θ - 2π) = 3 cot(θ) =3(-2√6) = -6√6